C is for Collider

In this post, we will learn a little more about the world’s largest particle accelerator, the Large Hadron Collider (LHC).

Do you remember a few years ago when there was a lot of fuss about a black hole being created? I know there were a few nervous questions fired at our unfortunate science teacher that day.

Proton beams in the LHC can at least enjoy a few thousand trips through the scenic Alpine countryside before being annihilated | Image: CERN

The reason for all that fuss is situated 175 metres underground, on the border between France and Switzerland. The LHC is a circular tunnel with a diameter of 27 kilometres, where scientists and engineers are working to solve some of the big unanswered questions in physics.

But how does this machine work, and how is it going to help?

Well, as the name suggests, colliding is a pretty big part of the whole idea. This machine usually uses protons (the positive subatomic particle) but can sometimes use the whole nucleus of the material lead. Remember what they are? If not, we’ve already covered a bit about what protons are.

Naturally, it’s not as easy as just throwing them at each other and observing what happens. The particles are so small that the chance of getting a successful collision is described by the creators themselves as about as likely as “firing two needles 10 kilometres apart with such precision that they meet halfway.”

Hmmmm, not easy stuff then.

Rumour has it that to make sure the LHC’s superconducting electromagnets were cold enough, CERN hired a group of Canadians to touch them, and were only satisfied when they admitted “they’re pretty chilly, eh?” On a side note, you shouldn’t believe everything you read on the internet | Image: MaGIc2laNTern

To add to the complications, the particles must be going at almost the speed of light to have enough impact when (or if) they do collide for anything to happen. The Large Hadron Collider is designed to help speed up the particles using thousands of seriously strong magnets. These magnets actually have a pretty impressive name, officially they are superconducting electromagnets. There’s your dinner party lingo for the day!

With all that whizzing around and accelerating you’d imagine things are getting pretty hot down there, right? Well, no. Another complication arises. In order for the electromagnets to work they must be kept at -271.3 °C. That’s colder than outer space! In order to achieve this, a complicated cooling system is in place which uses liquid helium to keep things chilly.

I’m beginning to understand why this project is such a big deal.

But what is it all for?

Collision data for the Higgs event. When your raw data looks this cool, it’s not too hard to persuade anyone that your research is justified | Image: Lucas Taylor/ CERN

Well, sometimes science for science’s sake is a good enough reason to conduct an experiment. However when setting up that experiment cost an estimated £6.2 billion and involves over 10,000 scientists and engineers in an international collaboration you need a slightly better excuse.

The team at the European Organisation for Nuclear Research (CERN) have certainly got more than one decent reason for this mammoth undertaking. They hope to answer some fundamental questions about the structure of space and time, to better understand forces which are part of our lives every day and even to discover brand new particles. In July 2012 the team announced the discovery of the Higgs boson, a particle which will now be studied intensively to help answer some of these big questions.

The Large Hadron Collider is at the forefront of some of the most profound scientific discoveries of our time and we should certainly stay tuned for more exciting discoveries. If you’re interested in finding out more visit the CERN website which even includes a virtual tour of the tunnel itself.